"We did the best we could and played the game in the right way but once we had conceded the first goal we couldn't get any control of the game."

Three goals in nine minutes early in the second half made the difference for La Viola, who failed to get out of the group stages last season.

Fiorentina began brightly with Adrian Mutu beating two men on the left before his cross was blocked behind with captain Dario Dainelli heading wide from the corner in the 5th minute.

The Hungarians lost Adam Komlosi to injury early on and Fiorentina exposed the subsequent confusion on 14 minutes as Marco Marchionni played a one-two with Alberto Gilardino that split Debrecen's defence wide open before crossing for Mutu to head past Djordje Pantic.

Gilardino then clipped the top of the crossbar with a header from Juan Vargas's corner on 34 minutes.

By then the hosts had also been forced into a defensive change as Alessandro Gamberini limped off to be replaced by Per Kroldrup and they too were soon made to pay.

Debrecen equalised out of the blue on 38 minutes as captain Leandro sent a deep cross over from the left and Gergely Rudolf did brilliantly to get on the end of it ahead of Kroldrup and poke it past Vlada Avramov.

Fiorentina came close to retaking the lead immediately but Pantic made a stunning save from Gilardino.

Fiorentina took control from the restart as Gilardino shot wide and Marchionni's effort was tipped around the post by Pantic who then saved on the line from Danielli's poke from the resulting corner.

Fiorentina were all over the visitors and Pantic saved with his foot from Mutu and then palmed away substitute Riccardo Montolivo's volley.

But finally on 52 minutes he was beaten in the air by Dainelli who headed home Comotto's high cross.

Montolivo then doubled the advantage on 59 minutes as Vargas's cross found it's way to the back post and the substitute volleyed home.

Two minutes later it started to become a rout as slick passing played Marchionni into the box and he dinked the ball over Pantic.

But 20 minutes from time Debrecen had a lifeline when their substitute Adamo Coulibaly converted at the back post.

But minutes later Gilardino flicked a header home from Vargas's free-kick as Debrecen's woeful defence crumbled again.